(24:15) When you received it with your tongues and said with your mouths that of which you had no knowledge and thought it was insignificant while it was, in the sight of Allah, tremendous.
Muhammad Taqi-ud-Din al-Hilali and Muhammad Muhsin Khan,
(24:15) When you were propagating it with your tongues, and uttering with your mouths that whereof you had no knowledge, you counted it a little thing, while with Allah it was very great.
Mohammed Marmaduke William Pickthall
(24:15) When ye welcomed it with your tongues, and uttered with your mouths that whereof ye had no knowledge, ye counted it a trifle. In the sight of Allah it is very great.
Abdullah Yusuf Ali
(24:15) Behold, ye received it on your tongues, and said out of your mouths things of which ye had no knowledge; and ye thought it to be a light matter, while it was most serious in the sight of Allah.
Mohammad Habib Shakir
(24:15) When you received it with your tongues and spoke with your mouths what you had no knowledge of, and you deemed it an easy matter while with Allah it was grievous.
Dr. Ghali
(24:15) As you received it on your tongues and were saying with your mouths that of which you had no knowledge and reckoned it was a simple thing, and in the Reckoning of Allah it is a tremendous thing.
Ali Unal
(24:15) Just think how you welcomed it with your tongues from one another and uttered with your mouths something about which you had no knowledge. You deemed it a trifle whereas in Gods sight it was most grave.
Amatul Rahman Omar
(24:15) When (some of) you began to learn this (slander) from each others tongues, you gave tongue to that (rumour and made statements) of which you had no knowledge
Literal
(24:15) When you receive it with your tongues/languages and you say with your mouths what knowledge is not for you with it (you have no knowledge of) and you think/suppose it (is) easy/light, and it is at God great.
Ahmed Ali
(24:15) When you talked about it and said what you did not know, and took it lightly — though in the sight of God it was serious —
A. J. Arberry
(24:15) When you received it on your tongues, and were speaking with your mouths that whereof you had no knowledge, and reckoned it a light thing, and with God it was a mighty thing —
Abdul Majid Daryabadi
(24:15) When ye were publishing it with your tongues and saying that with your mouths of which ye had no knowledge. Ye deemed it light, and it was with Allah mighty!
Maulana Mohammad Ali
(24:15) And were it not for Allah’s grace upon you and His mercy in this world and the Hereafter, a grievous chastisement would certainly have touched you on account of the talk you indulged in.
Muhammad Sarwar
(24:15) Your tongues moved and your mouths spoke of something of which you had no knowledge. You thought it to be a trivial matter, while in the eyes of God it is blasphemy.
Hamid Abdul Aziz
(24:15) And but for the grace of Allah upon you, and His mercy in this world and the Hereafter, an awful doom would have seized you, for that which you glibly and hastily spread abroad.
Faridul Haque
(24:15) When you rumoured with your tongues after hearing such matters, and uttered with your mouths about which you had no knowledge, and you considered it light
Talal Itani
(24:15) When you rumored it with your tongues, and spoke with your mouths what you had no knowledge of, and you considered it trivial; but according to God, it is serious.
Ahmed Raza Khan
(24:15) When you rumoured with your tongues after hearing such matters, and uttered with your mouths about which you had no knowledge, and you considered it light; and that, in the sight of Allah, is very great.
Wahiduddin Khan
(24:15) When you were spreading it with your tongues and saying with your mouths things of which you had no knowledge, you considered it to be a trivial matter, but, in God’s sight, it was very serious.
Safi-ur-Rahman al-Mubarakpuri
(24:15) When you were propagating it with your tongues, and uttering with your mouths that whereof you had no knowledge, you counted it a little thing, while with Allah it was very great.
Ali Quli Qarai
(24:15) when you were receiving it on your tongues, and were mouthing something of which you had no knowledge, supposing it to be a light matter, while it was a grave [matter] with Allah.
Hasan al-Fatih Qaribullah and Ahmad Darwish
(24:15) You carried with your tongues and uttered with your mouths what you did not know. You have thought it a trifle, but before Allah it was a mighty thing.
That is translated surah An Nur ayat 15 (QS 24: 15) in arabic and english text, may be useful.