Treasury of Scripture Knowledge
Summary
                            Now the Levites were numbered from the age of thirty years and upward: and their number by their polls, man by man, was thirty and eight thousand.                        
                    The levites
Thirty and eight
General references
Bible References
The levites
                                        Numbers 4:2                                        
                                                            
                        Reckon up the sum of the sons of Kohath, out of the midst of the sons of Levi, - by their families by their ancestral house:
                                    Thirty and eight
                                        Numbers 4:48                                        
                                                            
                        yea, they who were numbered of them were found to be - eight thousand, and five hundred, and eighty.
                                    General references
                                        Numbers 4:35                                        
                                                            
                        from thirty years old and upwards, even unto fifty years old, all that might enter the host, to labour in the tent of meeting;