While he was in the highest part of the horizon.
meaning, Jibril rose to the highest part of the horizon, according to Ikrimah and several others;
Ikrimah said,
"The highest horizon where the morning comes from."
Mujahid said, "It is (the place of) sunrise."
Qatadah said, "That from which the day comes."
Ibn Zayd and several others said similarly.
Imam Ahmad recorded that Abdullah bin Mas`ud said,
"The Messenger of Allah saw Jibril in his original shape having six hundred wings, each wing filling the side of the horizon, with a colorful array, and pearls and rubies falling from each wing as much as only Allah knows."
Only Imam Ahmad collected this Hadith.
Imam Ahmad recorded that Abdullah bin Abbas said,
"The Prophet asked Jibril to appear himself to him in his original shape and Jibril said to him, `Invoke your Lord.'
The Prophet invoked his Lord the Exalted and Most Honored, and a great huge figure appeared to him from the east and kept rising and spreading.
When the Prophet saw Jibril in his original shape, he was knocked unconscious. Jibril came down and revived the Prophet and wiped the saliva off of his cheeks."'
Only Ahmad collected this Hadith.
Meaning of "at a distance of two bows' length or less
Allah's statement,
ثُمَّ دَنَا فَتَدَلَّى