All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Our answer to your question is summarized in the following points:
Firstly, the Hadeeth that you mentioned is authentically attributed to the Prophet, sallallaahu ‘alayhi wa sallam, and classified as Saheeh (authentic). It was narrated by Imam Ahmad and classified as Saheeh by Ahmad Shaakir and Al-Albaani . It was cited in Saheeh Al-Jaami‘ no.1629, and As-Silsilah As-Saheehah no.1602.
Secondly, the meaning of the Hadeeth was authentically narrated in Saheeh Al-Bukhaari as well with the word Haqw (waist) in its text (instead of Hujzah). It was narrated on the authority of Abu Hurayrah that the Prophet, sallallaahu ‘alayhi wa sallam, said: “Allah created the creation, and when He had finished it, the Rahim (womb) got up and caught hold of the Haqw (Waist) of Allah, whereupon, Allah said, ‘What is the matter?’ It said, ‘I seek refuge with You from those who sever the ties of kinship.’ Allah Said, ‘Will you be satisfied if I bestow My favors upon those who maintain your ties and withhold My favors from those who sever your ties?’ It said, ‘Yes, O my Lord!’ Then Allah said, ‘That is for you (i.e. your request is granted).’” Abu Hurayrah added: “If you wish, you may recite the Saying of Allah, The Exalted (which means): {So would you perhaps, if you turned away, cause corruption on earth and sever your [ties of] kinship?} [Quran 47:22]”
Thirdly, concerning the meaning of the word Hujzah, Al-Albaani said in As-Silsilah As-Saheehah: “Hujzah means the waist, around which the Izaar (loincloth or waist-wrap) is fastened. The Arabs say, ‘He took hold of his Hujzah,’ meaning he sought refuge with him and asked him for help, as underlined in Arabic dictionaries.” [End of quote]
The word Haqw denotes the same meaning, i.e. waist, and is also used to refer to the Izaar itself, as in the Hadeeth narrated on the authority of Umm ‘Atiyyah : “So he gave her his Haqw and said, ‘Shroud her in it,’ meaning in his Izaar.” Ibn Hajar said in Fat-h Al-Baari: “Haqw, in principle, is the waistline, around which the Izaar is fastened, and it was used in this Hadeeth metaphorically to refer to the Izaar itself.” [End of quote]
Fourthly, as long as the Hadeeth is authentically attributed to the Prophet, sallallaahu ‘alayhi wa sallam, it is obligatory to believe in the meanings it includes, and it is not a condition for the acceptance of a Hadeeth and for belief in it that it should be cited in four of the Sunnah books or in the most authentic among them. Rather, it is obligatory to believe in any Hadeeth that is authentically attributed to the Prophet, sallallaahu ‘alayhi wa sallam, even if it was not cited in Saheeh Al-Bukhaari and Saheeh Muslim.
Fifthly, the word Haqw or Hujzah used in this Hadeeth renders it one of the texts addressing the Attributes of Allah, The Exalted, and accordingly, it must be affirmed and understood according to the apparent indication of the wording without Ta’weel (figurative interpretation), Takyeef (i.e. explaining how the Attributes are), or Tamtheel (i.e. drawing resemblance and likeness between Allah and the creation). We believe and affirm that Allah, The Exalted, has two Hands, Hearing, and Sight and that such Attributes are not like those of human beings. We do not figuratively interpret them, and we refer knowledge about their nature (how these Attributes are) to Him, acting upon His Saying (which means): {He (Allah) knows what happens to them (His creatures) in this world, and what will happen to them (in the Hereafter) but they will never encompass anything of His Knowledge.} [Quran 20:110] The same applies to the Attributes used in this Hadeeth. Al-Qaadhi Abu Ya‘la said in Ibtaal At-Ta’weelaat: “Know that it is not intellectually inconceivable that this report should be interpreted according to the apparent meaning of the wording and that the Haqw and Hujzah are among the Essence-Related Attributes of Allah; they do not actually refer to a body organ or part, and that the womb will hold on to it, not in the sense of touching and direct contact, but we should rather use such words as they are used in the Sharee‘ah texts. A similar example is the interpretation of placing His Foot in Hellfire, according to the apparent meaning of the wording, and the fact that Prophet Daawood (David) took hold of His Foot. In both contexts, the Foot of Allah is not interpreted as to refer to an actual body part, nor are any touching and direct contact involved. Just as we affirmed that He created Aadam (Adam) with His two Hands, being among His Essence-Related Attributes, and that the creation with them did not involve touching nor direct contact, the same applies here. Likewise, we affirmed the attribute of Istiwaa’ (being firmly seated/established on the Throne) not in the sense of attributing physical directions to Him nor suggesting touching and direct contact. Our Shaykh Abu ‘Abdullaah cited this Hadeeth in his book and interpreted it according to the apparent meaning of the wording, and this was also the apparent indication of Ahmad’s statement in this regard.” [End of quote]
Sixthly, it is not mentioned in the Quran or the Sunnah, as far as we know, that the attributes you mentioned: chest, etc. were ascribed to Allah, The Exalted.
Seventhly, Shaykh Ibn ‘Uthaymeen said: “Delving deep into such matters is wrong because the Messenger of Allah, sallallaahu ‘alayhi wa sallam, said: ‘Ruined are those who indulge in pointless and hair-splitting discussions.’ He did not say it once but repeated it thrice! As far as such matters pertinent to the Unseen are concerned, you should accept what is authentically reported and disregard what was not mentioned. This applies to the matters pertaining to the Attributes of Allah or what is more momentous; we must not discuss them with greater reason. This is contrary to the attitude of some students of religious knowledge who say: ‘We want to research the creed-related issues,’ and raise questions about creed-related matters which the Companions did not ask about nor were explained in the Quran and Sunnah. We should beware of such attitude as well.” [End of quote]
Allah Knows best.