(34:21) And he had over them no authority except [it was decreed] that We might make evident who believes in the Hereafter from who is thereof in doubt. And your Lord, over all things, is Guardian.
Muhammad Taqi-ud-Din al-Hilali and Muhammad Muhsin Khan,
(34:21) And he (Iblis Satan) had no authority over them, except that We might test him, who believes in the Hereafter from him who is in doubt about it. And your Lord is a Hafiz over everything. (AllKnower of everything i.e. He keeps record of each and every person as regards deeds, and then He will reward them accordingly).
Mohammed Marmaduke William Pickthall
(34:21) And he had no warrant whatsoever against them, save that We would know him who believeth in the Hereafter from him who is in doubt thereof; and thy Lord (O Muhammad) taketh note of all things.
Abdullah Yusuf Ali
(34:21) But he had no authority over them,- except that We might test the man who believes in the Hereafter from him who is in doubt concerning it: and thy Lord doth watch over all things.
Mohammad Habib Shakir
(34:21) And he has no authority over them, but that We may distinguish him who believes in the hereafter from him who is in doubt concerning it; and your Lord is the Preserver of all things
Dr. Ghali
(34:21) And in no way did he have any all-binding authority over them, except that We would know him who believed in the Hereafter from him who was in doubt thereof. And your Lord is Ever-Preserving over everything.
Ali Unal
(34:21) And yet, he had no authority over them (to compel them to do anything), except in that (by testing humankind through him) We distinguish those who truly believe in the Hereafter from those who are in doubt concerning it. Your Lord keeps watch and record of all things.
Amatul Rahman Omar
(34:21) Though he (- Iblîs) had no authority over them (for it is by their own wrong beliefs and evil deeds that mankind brings about their spiritual ruin). (It happened thus) so that We might distinguish those who believed in the Hereafter from those who were suffering from doubts about it. Indeed, your Lord is Watchful over and Preserver of everything.
Literal
(34:21) And nothing from a power/authority/control was for him on them, except to know who believes with (in) the end (other life) than who he is from it in doubt/suspicion, and your Lord (is) on every thing (an) honest protector/observor .
Ahmed Ali
(34:21) He had no authority over them save for the purpose of Our knowing who believed in the world to come, and who doubted it. For your Lord keeps a watch over everything.
A. J. Arberry
(34:21) Yet he had no authority over them, but that We might know him who believed in the Hereafter from him who was in doubt thereof Thy Lord is Guardian over everything.
Abdul Majid Daryabadi
(34:21) And he hath no authority over them except that We would know him who believeth in the Hereafter from him who is in doubt thereof. And thy Lord is over everything a Warden.
Maulana Mohammad Ali
(34:21)-
Muhammad Sarwar
(34:21) He did not have any authority over them except to the extent that would allow Us to know who had faith in the life to come and who had doubts about it. Your Lord is a Guard over all things.
Hamid Abdul Aziz
(34:21) And certainly Satan found true his calculations concerning them, so they follow him, except a party of the believers.
Faridul Haque
(34:21) And Satan had no control over them at all, except that We willed to reveal as to who believes in the Hereafter and who is in doubt of it
Talal Itani
(34:21) He had no authority over them; except that We willed to distinguish him who believes in the Hereafter, from him who is doubtful about it. Your Lord is Guardian over all things.
Ahmed Raza Khan
(34:21) And Satan had no control over them at all, except that We willed to reveal as to who believes in the Hereafter and who is in doubt of it; and your Lord is a Guardian over all things.
Wahiduddin Khan
(34:21) but he had no authority over them; We only desired to distinguish those who believed in the Hereafter from those who were in doubt concerning it. Your Lord is watchful over all things.
Safi-ur-Rahman al-Mubarakpuri
(34:21) And he had no authority over them, — except that We might test him who believes in the Hereafter, from him who is in doubt about it. And your Lord is Watchful over everything.
Ali Quli Qarai
(34:21) He had no authority over them, but that We may ascertain those who believe in the Hereafter from those who are in doubt about it, and your Lord is watchful over all things.
Hasan al-Fatih Qaribullah and Ahmad Darwish
(34:21) Yet he had no authority over them except that We would know who believed in the Everlasting Life, from he who doubted. Your Lord is the Watcher over all things.
That is translated surah Saba ayat 21 (QS 34: 21) in arabic and english text, may be useful.