All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
It is impermissible for a Muslim to tell a lie unless lying serves a Sharee‘ah interest which cannot be realized except by swearing. Averting harm from a Muslim is a Sharee‘ah-considered interest which makes lying allowable. But it is impermissible for one to lie so long as he could avert harm by means of equivocation and multi-connotative statements since the one who uses equivocation is truthful in what he says. It is narrated on the authority of Suwayd ibn Hanthalah that he said: “We set out with the intention to go to the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, and we had Waa’il Ibn Hujr with us who was seized by one of his enemies, and the people felt uncomfortable to swear. Thereupon I swore that he was my brother, so he was released. We came to the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, and I mentioned that to him and he said: “No doubt, you have been the most dutiful and the truest of them all. You are true: a Muslim is the brother of a Muslim.”
Hence, there is no blame on this person to tell such a lie and swear to it in order to avert harm from his wronged Muslim brother if this is the only way to achieve this aim.
Allaah Knows best.