Surah 2. Al-Baqara, Ayah 142

Before his call to prophethood, and during the early Meccan period of his ministry, the Prophet - and his community with him - used to turn in prayer towards the Ka'bah. This was not prompted by any specific revelation, but was obviously due to the fact that the Ka'bah - although it had in the meantime been filled with various idols to which the pre-Islamic Arabs paid homage - was always regarded as the first temple ever dedicated to the One God (cf. 3:96 ). Since he was aware of the sanctity of Jerusalem - the other holy centre of the unitarian faith - the Prophet prayed, as a rule, before the southern wall of the Ka'bah, towards the north, so as to face both the Ka'bah and Jerusalem. After the exodus to Medina he continued to pray northwards, with only Jerusalem as his qiblah (direction of prayer). About sixteen months after his arrival at Medina, however, he received a revelation (verses {142-150} of this surah) which definitively established the Ka'bah as the qiblah of the followers of the Qur'an. This "abandonment" of Jerusalem obviously displeased the Jews of Medina, who must have felt gratified when they saw the Muslims praying towards their holy city; and it is to them that the opening sentence of this passage refers. If one considers the matter from the historical point of view, there had never been any change in the divine commandments relating to the qiblah: there had simply been no ordinance whatever in this respect before verses {142-150} were revealed. Their logical connection with the preceding passages, which deal, in the main, with Abraham and his creed, lies in the fact that it was Abraham who erected the earliest structure of the temple which later came to be known as the Ka'bah.

Or: "He guides onto a straight way him that wills [to be guided]".

 For about sixteen months after daily prayers became obligatory, Muslims used to face towards Jerusalem before the order came to face a new qiblah (direction of prayer)—the Sacred Mosque in Mecca.

Nas - People, the unthinking multitude that sway to and fro, instead of being firm in God's Way. The reference here is to the idolaters, the Hypocrites, and the party of Jews who were constantly seeking to "entangle in their talk" Mustafa and his disciples in Medina even as the Pharisees and the Sadducees of Jesus's day tried to entangle Jesus (Matt. xxii, 15, 23)

Nas - People, the unthinking multitude that sway to and fro, instead of being firm in God's Way. The reference here is to the idolaters, the Hypocrites, and the party of Jews who were constantly seeking to "entangle in their talk" Mustafa and his disciples in Medina even as the Pharisees and the Sadducees of Jesus's day tried to entangle Jesus (Matt. xxii, 15, 23)