New International Version
As he was praying, the appearance of his face changed, and his clothes became as bright as a flash of lightning.

American Standard Version
And as he was praying, the fashion of his countenance was altered, and his raiment became white and dazzling.

Berean Study Bible
And as He was praying, the appearance of His face changed, and His clothes became radiantly white.

Douay-Rheims Bible
And whilst he prayed, the shape of his countenance was altered, and his raiment became white and glittering.

English Revised Version
And as he was praying, the fashion of his countenance was altered, and his raiment became white and dazzling.

King James Bible
And as he prayed, the fashion of his countenance was altered, and his raiment was white and glistering.

World English Bible
As he was praying, the appearance of his face was altered, and his clothing became white and dazzling.

Young's Literal Translation
and it came to pass, in his praying, the appearance of his face became altered, and his garment white -- sparkling.

Luke 9:29 Additional Translations ...