The promise means to commit oneself by a pledge to do or give. Fulfilling a promise is the most positive and greatest quality of a person. There is nothing comparable to it. According to the Islamic teaching, the promise is not simply part of social ethics, it is a responsible pledge for which man is accountable before God. The Qur’an says in the chapter Al-Isra’ (The Night Journey): Keep your promises. You will be called to account [before God] for every promise which you have made. (17:34).
In another verse in the chapter Al-Saff (Ranks), the Qur’an says: O you who believe! Why do you say that which you do not do? It is most hateful to God that you say that which you do not. (61:3)
To not fulfill a promise is a very wrong habit. It bears serious consequences for a man. To break a promise may ruin the whole personality of a human being. This habit and spirituality cannot coexist. If one makes promises and fails to fulfill them, then this habit may lead to the nonexistence of all positive qualities. In social life, a person possessing this habit loses his credibility. He will not be regarded as having a predictable character, which is the greatest social value of a person. Keeping promises is one’s social identity. A person who loses this social identity will lose his social status.
The greatest danger of this habit is that such a person will be presented before God on the Day of Judgement and will be asked by Him: ‘Why did you fail to fulfill the promise after having pledged it?’ It means that this habit has grave consequences because a person of this kind takes the risk of being disgraced in the eyes of God. Without doubt, there is no loss greater than this. Breaking a promise is a very bad habit. It is so bad that even a small kind of breaking of the promise is very serious in nature as its grave kind.