Sahih Muslim | Book 7 | Chapter 74

Narrated by Abdullah b. 'Umar
Abdullah b. 'Umar reported that whenever Allah's Messenger (may peace be upon him) came back from the battle or from expeditions or from Hajj or Umra and as he reached the top of the hillock or upon the elevated hard ground, he uttered Allah-O-Akbar thrice,and then said: There is no god but Allah. He is One, there is no partner with Him, His is the sovereignty and His is the praise and He is Potent over everything. (We are) returning, repenting, worshipping, prostrating before our Lord, and we praise Him Allah fulfilled His promise and helped His servant, and routed the confederates alone.
Narrated by Ibn Umar
This hadith has been narrated on the authority of Ibn Umar through another chain of transmitters (but with one alteration) that here Allah-o-Akbar is mentioned twice.

Narrated by Anas b. Malik (Allah be pleased with him)
Anas b. Malik (Allah be pleased with him) reported: I and Abu Talha (both) came back along with Allah's Apostle (may peace be upon him). Safiyyah (the wife of the Holy Prophet) rode behind him on his camel and as we came to the out-skirts of Medina he said: (We are those) who return, who repent, who worship our Lord, who praise (Him), and he went on uttering this until we entered Medina.

Narrated by Anas
A hadith like this has been narrated by Anas b. Malik (Allah be pleased with him) through another chain of transmitters.