The Quran

قالَ الَّذي عِندَهُ عِلمٌ مِنَ الكِتابِ أَنا آتيكَ بِهِ قَبلَ أَن يَرتَدَّ إِلَيكَ طَرفُكَ ۚ فَلَمّا رَآهُ مُستَقِرًّا عِندَهُ قالَ هٰذا مِن فَضلِ رَبّي لِيَبلُوَني أَأَشكُرُ أَم أَكفُرُ ۖ وَمَن شَكَرَ فَإِنَّما يَشكُرُ لِنَفسِهِ ۖ وَمَن كَفَرَ فَإِنَّ رَبّي غَنِيٌّ كَريمٌ

Muhammad Asad

Answered he who was illumined by revelation:¹ "[Nay] as for me - I shall bring it to thee ere the twinkling of thy eye ceases!"² And when he saw it truly before him,³ he exclaimed: "This is [an outcome] of my Sustainer's bounty, to test me as to whether I am grateful or ungrateful!⁴ However, he who is grateful [to God] is butgrateful for his own good; and he who is ungrateful [should know that], verily, my Sustainer is self-sufficient, most generous in giving!"

Lit., "he who had knowledge out of (or "through"] revelation (al-kitab)" - i.e., Solomon himself (Razi).
I.e., faster than any magic could achieve: thus alluding to the symbolic nature of the forthcoming appearance of the "throne". Here, as in the whole of the story of Solomon and the Queen of Sheba, symbolism and legendary "fact" are subtly intertwined, evolving into an allegory of the human soul's awakening to a gradual realization of spiritual values.
Lit., "established before him". Since the verbal form istaqarra and its participle mustaqirr often indicate no more than that something "has being" or "exists" (cf. Lane VII, 2500), the phrase ra'ahu mustaqirran 'indahu may be understood as "he saw it being [i.e., actually] before him": hence my rendering.
I.e., "whether I attribute my spiritual powers to God or, vaingloriously, to myself".