Is this hadeeth saheeh?.
This hadeeth is not saheeh, and it is not proven from the Prophet (peace and blessings of Allaah be upon him).
Al-Bayhaqi narrated in Shu’ab al-Eeman (3/1437) from ‘Abd-Allaah ibn Abi Awfa (may Allaah be pleased with him) that the Prophet (peace and blessings of Allaah be upon him) said: “The sleep of the fasting person is worship, his silence is tasbeeh, his du’aa’ is answered and his good deeds will be multiplied.” Its isnaad was classed as weak by al-Bayhaqi who said: Ma’roof ibn Hassaan (one of the men in the isnaad) is da’eef (weak) and Sulaymaan ibn ‘Amr al-Nakha’i is weaker than him. Al-‘Iraqi said in Takhreej Ihya’ ‘Uloom al-Deen (1/310): Sulaymaan al-Nakha’i is one of the liars. It was classed as da’eef by al-Manaawi in Fayd al-Qadeer (9293) and it was mentioned by al-Albaani in Silsilat al-Ahaadeeth al-Da’eefah (4696) who said: It is da’eef.
What the Muslims should do in general – and this applies even more so to khateebs and daa’iyahs – is to verify reports before attributing a hadeeth to the Messenger of Allaah (peace and blessings of Allaah be upon him). It is not permissible to attribute to him anything that he did not say. He (peace and blessings of Allaah be upon him) said: “Telling a lie about me is not like telling a lie about anyone else. Whoever tells a lie about me deliberately, let him take his place in Hell.” Narrated by al-Bukhaari (1391) and by Muslim in the introduction to his Saheeh (4).
And Allaah knows best.