Acts 1:21
Wherefore of these men which have companied with us all the time that the Lord Jesus went in and out among us,
Cross-reference
Acts 9:28 describes Paul moving freely with the apostles, but he was not with Jesus from John's baptism — highlighting his ineligibility for the Twelve.
Acts 6:3 shows a similar selection process for deacons — choose men from among yourselves, echoing the criteria for choosing an apostle.
Numbers 27:17 shows Moses asking for a successor so Israel won't be scattered—the apostles similarly fill the gap left by Judas.
John 15:27 says 'you have been with me from the beginning' and will bear witness—directly matching the criteria for Judas' replacement.
Luke 1:2 refers to eyewitnesses from the beginning — exactly the qualification required for the apostolic replacement in Acts.
Deuteronomy 1:13 shows Moses selecting leaders from the congregation — a pattern for choosing a replacement from among those who accompanied Jesus.
2 Samuel 5:2 uses 'led out and brought in' to describe David's shepherding—the same idiom for leadership appears in Acts 1:21.
1 Kings 3:7 has Solomon confessing inexperience in going out and coming in—the same idiom used in Acts 1:21 for apostles' experience.