1 Samuel 3:20
And all Israel from Dan even to Beer–sheba knew that Samuel was established to be a prophet of the Lord.
Cross-reference
In 1 Samuel 9:6, Samuel is called a 'man of God' whose words come true, reinforcing his established prophetic reputation.
In 1 Samuel 12:2, Samuel recalls his lifelong leadership, grounding his prophetic authority in his long service to Israel.
Judges 20:1 uses the same phrase 'from Dan to Beersheba' to describe all Israel gathering — reinforcing the geographical scope of Samuel's recognition.
2 Samuel 3:10 also uses 'from Dan to Beersheba' to describe the extent of David's kingdom — the same merism for all Israel.
2 Samuel 17:11 repeats 'from Dan to Beersheba' as a counsel to gather all Israel — identical idiom for the whole nation.
In Ezekiel 33:33, the people will know a prophet was among them, directly echoing the recognition of Samuel as a prophet.
In Acts 3:24, Peter says all prophets from Samuel onward foretold these days, explicitly affirming Samuel's prophetic role.
In Acts 13:20, Paul refers to 'Samuel the prophet', confirming his recognized prophetic office.