Explanation
The compiler—may Allah have mercy on him—cites in the Chapter on Fulfilling Covenants and Keeping Promises the hadith transmitted by Abu Hurayrah (may Allah be pleased with him): the Messenger of Allah (peace and blessings be upon him) said, “The signs of the hypocrite are three: when he speaks, he lies; when he makes a promise, he breaks it; and when he is entrusted, he betrays.”

“Sign” here means an identifying mark, and they are three: lying when speaking, reneging when promising, and betraying when entrusted. These, therefore, are among the distinguishing traits of the hypocrites. If you see a person who lies when he speaks, breaks his promises, and betrays the trusts placed in him, know that these are marks of hypocrisy—for the very foundation of hypocrisy rests on deception and concealment: he hides the evil and displays the good, conceals disbelief and outwardly shows faith.

The liar likewise conveys what is contrary to reality; the one who promises and then reneges does the same; and so does the one who betrays a trust. All of these are signs of hypocrisy—may Allah protect us.

This hadith warns against lying, for lying is one of the signs of the hypocrites, and it is therefore impermissible for a Muslim to lie. If, however, he is compelled to employ tauriyah (an indirect expression open to another interpretation), there is no harm in doing so—for example, if someone asks him about a matter he does not wish others to know and he speaks words outwardly at odds with reality but that admit a valid interpretation, there is no sin in that. As for breaking a promise, it is unlawful; one must fulfil his promise whether he promised