"I will redeem you with a stretched out arm, and with great judgments" Exodus 6:6

This is the first use of the word arm in the Bible, God offers redemption to his people Israel. 

The Stretched out Arm - A Metaphor for the Power and Salvation of God

From Exodus to Ezekiel the phrase "stretched out arm" is used of our God 14 times in the King James version.

• "redeem you with a stretched out arm, and with great judgments" Exodus 6;6
• "by a mighty hand, and by a stretched out arm"  Deuteronomy 4:34
• "Lord thy God brought thee out thence through a mighty hand and by a stretched out arm" Deuteronomy 5:15
• "the wonders, and the mighty hand, and the stretched out arm, whereby the Lord thy God brought thee out" Deuteronomy 7:19
• "they are thy people and thine inheritance, which thou broughtest out by thy mighty power and by thy stretched out arm." Deuteronomy 9:29
• "Lord your God, his greatness, his mighty hand, and his stretched out arm" Deuteronomy 11:2
• "they shall hear of thy great name, and of thy strong hand, and of thy stretched out arm" 1 Kings 8:42
• "Lord, who brought you up out of the land of Egypt with great power and a stretched out arm" 2 Kings 17:36
• "for thy great name's sake, and thy mighty hand, and thy stretched out arm" 2 Chronicles 6:32
• "With a strong hand, and with a stretched out arm: for his mercy endureth for ever" Psalm 136:12
• " Lord God! behold, thou hast made the heaven and the earth by thy great power and stretched out arm, and there is nothing too hard for thee... brought forth thy people Israel out of the land of Egypt with signs, and with wonders, and with a strong hand, and with a stretched out arm" Jeremiah 32:17 & 21
• "As I live, saith the Lord God, surely with a mighty hand, and with a stretched out arm... will gather you out of the countries wherein ye are scattered, with a mighty hand, and with a stretched out arm" Ezekiel 20:33-34