Maj.-Gen. Qassem Suleimani's message to militant factions resisting Israel's military operations in the Gaza Strip was published late Wednesday by Iran's official IRNA news agency.
Suleimani "underlined that confronting the Zionist enemy is a necessity and the Palestinian resistance movement will turn the land and sky into hell for the Zionists."
"Disarmament of resistance is a daydream that will only come true in the graveyard" for Israel, said the rarely quoted senior figure.
The United States and European countries have called for a cease-fire in the devastating Gaza conflict and the disarmament of militant groups in the coastal strip, notably Hamas.
The Quds Force, a branch of Iran's Revolutionary Guard, is highly secretive and conducts security functions abroad deemed necessary to protect the Islamic Republic.
As its leader, Suleimani is seldom mentioned or pictured in Iranian media but he has cultivated a reputation as one of the most influential security operatives in the Middle East.
"The painful scenes in Palestine dishearten us and fills our chests with deep grief arising from deep anger," his statement added. "Martyrdom for Palestine is a dream of every noble Muslim and freedom-seeker."
Suleimani's intervention follows a speech Tuesday by Iran's Supreme Leader Ayatollah Ali Khamenei, urging the Islamic world to arm the Palestinians and branding Israel's actions in Gaza a "genocide."
Last week, Iran's Parliament Speaker Ali Larijani said his country had provided Hamas with the technology it has used to rain down rockets on Israel from Gaza.