Ezekiel 2:1
וַיֹּאמֶר אֵלָי בֶּן-אָדָם עֲמֹד עַל רַגְלֶיךָ וַאֲדַבֵּר אֹתָךְ
He said to me, "Son of man, stand on your feet and I will address you."
"Ben Adam" (son of man) is a unique form of address used throughout the Book of Ezekiel. Metzudas David tells us that this term was used to keep the prophet Yechezkel (Ezekiel) grounded. Since he was being shown the vision of G-d's "chariot" and other hidden wonders, he needed to be reminded that he was still merely human and not one of the angels.