Allah Almighty says: {Whoever intercedes in a good cause will have a share in its reward} [Surat an-Nisā’: 85]
246/1- Abu Mūsa al-Ash‘ari (may Allah be pleased with him) reported that when someone came to him asking for something, he would turn towards those sitting with him and say: “Intercede and you will be rewarded, and Allah will decide what He loves on the tongue of His Prophet.” [Narrated by Al-Bukhāri and Muslim]
Another narration reads “what He wills” instead of “what He loves”.
247/2- Ibn ‘Abbās (may Allah be pleased with him and his father) reported regarding the story of Barīrah and her husband: “The Prophet (may Allah’s peace and blessings be upon him) said to her: ‘If you would return back to him?’ She said: ‘O Messenger of Allah, are you ordering me to do so?’ He replied: ‘I’m just interceding.’ So she said: ‘I have no need for him.’” [Narrated by Al-Bukhāri]
Intercession means to mediate in favor of someone for the purpose of bringing a benefit or warding off harm. The intercession that the author is referring to is that which occurs in the worldly life.
1) Interceding for something unlawful is cooperation in sin and transgression, like one who intercedes on behalf of someone who transgresses against others.
2) Interceding regarding a lawful matter is a form of favor done to others, and the doer earns a reward for that.
3) The Companions (may Allah be pleased with them) venerated the commands of the Messenger of Allah (may Allah’s peace and blessings be upon him). Look how Barīrah reacted when the Prophet (may Allah’s peace and blessings be upon him) said to her: ‘If you would return back to him?’ She asked the Messenger of Allah (may Allah’s peace and blessings be upon him) if he was ordering her, so that she would listen and obey. This is the attitude of the believer; as he/she hastens to comply with the command of Allah Almighty and the command of His Messenger (may Allah’s peace and blessings be upon him).