Imam Al-Nawawi’s Riyad-us-Saliheen
Chapter 30

Allah, the Exalted, says:

“Whosoever intercedes for a good cause will have the reward thereof.” (4:85)

246. Abu Musa Al-Ash`ari (May Allah be pleased with him) reported: Whenever a needy person would come to the Prophet (sallallaahu ’alayhi wa sallam), he would turn to those who were present and say, “If you make intercession for him, you will be rewarded, because Allah decreed what He likes by the tongue of His Messenger”.
[Al-Bukhari and Muslim].

247. Ibn `Abbas (May Allah bepleased with them), reported in connection with the case of Barirah  (May Allah bepleased with her) and her husband: The Prophet (sallallaahu ’alayhi wa sallam) said to her, “It is better for you to go back to your husband.” She asked: “O Messenger of Allah, do you order me to do so.” He replied, “I only intercede” She then said: “I have no need for him”.