The following is related by Al-Wahidi in his Asbab al-Nuzul [The Circumstances of Revelation] regarding Surah 38 verses 5 to 12
“When ‘Umar ibn al-Khattab embraced Islam, the Muslims were overjoyed while the Quraysh was devastated. Al-Walid ibn al-Mughirah said to the nobles and chiefs of Quraysh: ‘Go to Abu Talib and say to him: you are our elder and chief and you know well what these fools have done. We have come to you so that you judge between us and your nephew’. Abu Talib sent for the Prophet ﷺ and when he answered his call, he said to him: ‘Son of my brother, these are your own people and they are asking you for fairness, so do not swerve completely from them’. The Prophet ﷺ asked: ‘What do they want from me?’ They said: ‘Cease mentioning our deities and we will leave you alone with your God’. The Prophet ﷺ said to them: ‘Will you grant me one word [kalimah] by means of which you will rule over the Arabs and subjugate the non-Arabs?’ Abu Jahl said: ‘We will surely grant it and grant you ten like it!’ The Prophet ﷺ said: ‘Say: there is no deity except Allah!*’ The Quraysh were repelled and left, saying: ‘Does he make the gods One God? How can One God be sufficient for the whole creation?’ And so Allah, exalted is He, revealed about them these verses [i.e. from 38:5], up to His words (The folk of Noah before them denied (their messenger)…) [38:12]”
*i.e. La ilaha illa Llah