The baptism of John, whence was it? from heaven, or of men? And they reasoned with themselves, saying, If we shall say, From heaven; he will say unto us, Why did ye not then believe him? Matthew 21:25
By the time of the Second Temple, Jews had developed an aversion to using the name of God for fear of violating the Third Commandment. They substituted evasive synonyms for "God" such as "the Name" (an abbreviation of "the Name of the Lord"), "the Place," "the Power," and "Heaven" (as in Matthew 21:25). In the phrase "Kingdom of Heaven," this substitution is clearly seen.
In Luke 15:18 the Prodigal Son says, "I have sinned against Heaven..." There also, "Heaven" is a clear substitute for "God."
Bivin, David, and Roy Blizzard, Jr. 1994. Understanding the Difficult Words of Jesus: New Insights from a Hebraic Perspective. Shippensburg, PA: Destiny Image Publishers., pgs 58-59