Acts 2:1

And, when the day of Pentecost was being fulfilled they were all together in one place;

Acts 20:16

For Paul had determined to sail past Ephesus, that he might not have to spend time in Asia; for he was hastening, if it were possible for him, to be in Jerusalem on the day of Pentecost.

1 Corinthians 16:8

But I will remain at Ephesus until the Pentecost;

Acts 1:13-15

And, when they entered, they went up into the upper-room, where they were abiding; both Peter and John, and James, and Andrew, Philip, and Thomas, Bartholomew, and Matthew, James the son of Alphaeus, and Simon the Zealot, and Judas the son of James.

Acts 2:46

And they, continuing daily with one accord in the temple, and breaking bread at their homes, were partaking of food in gladness and singleness of heart;

Acts 4:24

And they, having heard it, lifted up their voice to God with one accord, and said, "Lord, Thou Who didst make the heaven and the earth and the sea, and all things in them;

Acts 4:32

And the heart and soul of the multitude of those who believed were one; and not even one was saying that any of the things belonging to him was his own, but they had all things common.

Acts 5:12

And through the hands of the apostles many signs and wonders were wrought among the people; and they were all with one accord in Solomon's porch.

Romans 15:6

that with one accord ye may, with one mouth, glorify the God and Father of our Lord Jesus Christ.

Philippians 1:27

Only demean yourselves in a manner worthy of the Gospel of Christ; that, whether coming and seeing you, or being absent, I may hear of your affairs, that ye are standing fast in one spirit, with one soul striving together for the faith of the Gospel;

Philippians 2:2

fill ye up my joy, that ye think the same thing; having the same love; united in soul; minding the one thing;

Treasury of Scripture Knowledge

Summary

And when the day of Pentecost was fully come, they were all with one accord in one place.

General references

Bible References

The day

Acts 20:16
For Paul had determined to sail past Ephesus, that he might not have to spend time in Asia; for he was hastening, if it were possible for him, to be in Jerusalem on the day of Pentecost.
1 Corinthians 16:8
But I will remain at Ephesus until the Pentecost;

They

Acts 2:46
And they, continuing daily with one accord in the temple, and breaking bread at their homes, were partaking of food in gladness and singleness of heart;
Acts 1:13
And, when they entered, they went up into the upper-room, where they were abiding; both Peter and John, and James, and Andrew, Philip, and Thomas, Bartholomew, and Matthew, James the son of Alphaeus, and Simon the Zealot, and Judas the son of James.
Acts 4:24
And they, having heard it, lifted up their voice to God with one accord, and said, "Lord, Thou Who didst make the heaven and the earth and the sea, and all things in them;
Acts 5:12
And through the hands of the apostles many signs and wonders were wrought among the people; and they were all with one accord in Solomon's porch.
Romans 15:6
that with one accord ye may, with one mouth, glorify the God and Father of our Lord Jesus Christ.
Philippians 1:27
Only demean yourselves in a manner worthy of the Gospel of Christ; that, whether coming and seeing you, or being absent, I may hear of your affairs, that ye are standing fast in one spirit, with one soul striving together for the faith of the Gospel;
Philippians 2:2
fill ye up my joy, that ye think the same thing; having the same love; united in soul; minding the one thing;

General references

Hebrews 13:1
Let brotherly love continue.