Acts 21:18 - Ellicott's Commentary On The Whole Bible

The day following Paul went in with us unto James... — Looking to Acts 20:16, it seems natural to infer that this was on or near the Day of Pentecost. The city would be crowded with pilgrims. The Church would be holding its solemn festival, not without memories of the great gifts of the Spirit, and prayers for their renewal. The Bishop of Jerusalem — to give him the title which, though apparently not then borne by him, expressed his functions, and was afterwards attached to his name — was there with the elders of the Church. St. Luke is careful to add that they were all there. On their part there was no reluctance to receive the Apostle of the Gentiles into full fellowship.