Isaiah 30:15 in the King James Version of the Bible reads: "For thus saith the Lord God, the Holy One of Israel; In returning and rest shall ye be saved; in quietness and in confidence shall be your strength: and ye would not."

This verse comes from the book of Isaiah in the Old Testament, which was written by the prophet Isaiah. The book of Isaiah contains messages of both judgment and hope for the people of Israel. In this particular verse, God is speaking to the Israelites through the prophet Isaiah, urging them to turn back to Him and find their salvation in Him.

The verse begins with "For thus saith the Lord God, the Holy One of Israel," emphasizing the authority and holiness of God. This sets the tone for the message that follows, indicating that what is stated is not just the prophet's words but indeed the word of God Himself.

The verse goes on to say, "In returning and rest shall ye be saved; in quietness and in confidence shall be your strength." This part of the verse is often seen as a call to repentance and trust in God. The language used here is deeply caring and reassuring, as God offers His people a way to find salvation, strength, and peace. The idea of "returning and rest" suggests a turning back to God and finding refuge in Him. It is an invitation to cease striving and find rest in God's presence. This rest involves both physical and spiritual rest, as well as a rest from striving to earn one's own salvation.

The phrase "in quietness and in confidence shall be your strength" further emphasizes the need for trust in God. Instead of relying on their own strength or seeking security in worldly things, the Israelites are encouraged to find strength in being still before God and having confidence in His faithfulness. This echoes the sentiment of Psalm 46:10, which says, "Be still, and know that I am God."

The verse concludes with the statement: "and ye would not." This part of the verse highlights the people's disobedience and unwillingness to heed God's call. Despite the offer of salvation, rest, strength, and confidence in Him, the Israelites chose to go their own way and reject God's invitation.

In the context of the book of Isaiah, this verse is part of a larger message of warning and hope for the people of Israel. The prophet Isaiah denounces the Israelites' reliance on foreign nations for protection and their disobedience to God's laws. He warns them of the consequences of their actions and urges them to turn back to God. At the same time, Isaiah offers hope and reassurance, pointing to the faithfulness and mercy of God if the people would only repent and trust in Him.

The themes present in Isaiah 30:15 include repentance, trust in God, disobedience, and the offer of salvation and rest. The verse is a reminder that true strength and salvation are found in resting in God and trusting in His faithfulness, rather than in our own efforts or the things of this world.

Symbolically, this verse can be seen as a foreshadowing of the rest and salvation that comes through Jesus Christ. In the New Testament, Jesus invites all who are weary and burdened to come to Him and find rest (Matthew 11:28). His offer of salvation and the rest that comes from trusting in Him resonate with the message of Isaiah 30:15.

In conclusion, Isaiah 30:15 communicates a powerful message of repentance, trust in God, and the offer of salvation and rest. It serves as a timeless reminder that true strength and peace are found in returning to God and resting in His faithfulness. The verse also carries with it a warning about the consequences of disobedience and rejection of God's offer. In its broader context, this verse is a part of the prophetic message of hope and warning that runs throughout the book of Isaiah. It continues to speak to readers today, urging them to turn back to God and find their salvation and strength in Him.