The Greek eiskaleomai means to call someone in or invite them inside. It appears only in Acts 10:23 when Peter, having received the vision about clean and unclean animals, 'invited the men in (eiskalesamenos) to be his guests.' The three men sent from Cornelius arrived, Peter received them, and the next day they departed together for a Gentile household — the pivotal turning point in early mission.
The eiskaleomai in Acts 10:23 is a tiny word with massive theological weight. Peter calling these Gentile messengers into his host's house was a visible embodiment of the vision's meaning: 'Do not call anything impure that God has made clean' (Acts 10:15). Before his mind was fully convinced, his feet obeyed. He called them in. The next day he entered a Gentile home (Acts 10:27) — something previously forbidden. The gospel's expansion to the nations began with this act of hospitality: eiskaleomai, a simple invitation in.