“The one who does not give thanks to people does not give thanks to Allah (Subhanahu wa Tala)” – Reported by Bukhari in al-Adab al-Mufrad.
The Prophet, salah allahu ‘alayhi wa salam, said:
“Whoever has a favour done for him and says Jazaak Allaahu khayran (may Allaah reward you with good) has done his utmost to thank him.”Narrated by al-Tirmidhi, 2035; classed as saheeh by al-Albaani in Saheeh al-Tirmidhi.
Allahumma a-inni ala Zikrika wa shukrika wa husni ibadatika
O Allah! Help me to remember you, to thank you, and to worship you in the best of manners
[Reference: Abu Dawud 2/86, An-Nasa'i 3/53. See also Al-Albani Sahih Abu Dawud 1 /284]