A compound of hote (when) and an (indefinite particle). Hotan introduces temporal clauses with the subjunctive mood, meaning 'whenever, at the time when' — often expressing a condition whose fulfillment is expected but the timing is uncertain or recurring.
The word hotan governs some of the most important conditional-temporal promises and warnings in the NT. John 16:13: 'When he, the Spirit of truth, comes, he will guide you into all the truth.' The hotan sets up a certain future reality — the Spirit's coming is assured; its transformative work is the promise. Matthew 6:2, 5, 16 — Jesus uses hotan three times in the Sermon on the Mount: 'When you give to the needy... when you pray... when you fast' — not 'if' but 'when.' These practices are assumed as normal disciplines of the kingdom life. 1 Corinthians 15:28: 'When he has done this, then the Son himself will be made subject to him who put everything under him' — describing the consummation of all things. The hotan of eschatology carries absolute certainty: the question is not whether these things will happen, but when the appointed time comes.