Linguistically Al-Mandoob is from An-Nadb (دبْ َّالن (and it is the Du’aa (supplication or beseeching) for something important.

The Mandoob according to the Shar’iy Istilaah (terminological convention) is:

That which the Shaari’ has requested to be done by way of a non-decisive request (Talab Ghair Jaazim).

It is said: It is that which the performer is rewarded for undertaking it whilst the one who does not do it is not punished. Examples of this include the Qawl of Allah Ta’Aalaa:

The command to write the debt is one of recommendation (An-Nadb) and not obligation (Al-Wujoob) because it is a Talab Ghair Jaazim (non-decisive request).

The term Naafilah can be used for some of the Mandoobaat like for the Tahajjud prayer during the night. Allah (swt) said:

The term Sunnah can also be used for some of the Mandoobaat like the Sunnah of Salaat us-Subh (Fajr), Azh-Zhohr, Al-‘Asr, Al-Maghrib and Al-‘Ishaa. This Sunnah could be Mu’akkadah like the Sunnah before Fajr and the Sunnah of the two ‘Eids just as the Sunnah could be Ghair-Mu’akkadah like the Sunnah of Salat ul-‘Asr.

Similarly, Mandoob can be used for acts like the Sadaqah, helping those in need and the congregational prayer (Salaat ul-Jamaa’ah).

The Hukm of Al-Mandoob is that its performer is deserving of the reward (Thawaab) from Allah whilst there is no punishment (‘Iqaab) for the one who leaves it. However, it is appropriate for the Muslim to perform a lot of the Mandoobaat in order to seek the reward of Allah, to build up his store of Hasanaat with Allah and for some of his Sayyi’aat (bad acts) that he may have slipped in to be forgiven. Allah (swt) said:

And the Mandoob is from the Hasanaat (good deeds).

The Messenger of Allah (saw) used to perform a lot in respect to the Mandoobaat and so for instance he would stand in the night in prayer until his feet would swell up. There are also Mandoobaat that are not valid to be left by the Ummah as a whole, such as marriage, because leaving it would mean the extinction of the Ummah. It is therefore Mandoob in relation to the individuals but Waajib in relation to the Jamaa’ah (collective). Al-Imaam Ash-Shaatibiy said in ‘Al-Muwaafaqaat’: “The leaving of the Mandoobaat as a whole has an effect upon the conditions of the Deen if the leaving was continuous (or permanent). If, however it was only on occasions then it would not affect it”. Therefore, undertaking the Mandoob is better and more appropriate than leaving it.

It has been named with this naming ‘An-Nadb’ because the Shaari’ has called and beseeched him and it has been called ‘Nafl’ because it represents an increase upon the Fard and it increases the reward. It has also been called At-Tatawwu’ (voluntary) because the one who undertakes it does so voluntarily and not under compulsion. The person undertakes it as a voluntary contribution beyond what is obliged upon (Al-Fard). And it has also been named ‘As-Sunnah’ because the Messenger of Allah (saw) introduced it and proceeded upon it.