It is clear that the elders Paul referred to in this section were the church overseers and not just any older men in the congregation. Paul had already given the qualifications for these officers ( 1 Timothy 3:1-7) and now he described them as ruling, preaching, and teaching. From this verse we learn that the overall duty of the elders was ruling the church in the sense of directing its affairs and giving oversight to all its activities (cf. 1 Peter 5:1-4). [source][source][source]
What were the single and double honor to which Paul referred? The single honor most likely alludes to the respect that came to the elder for being an elder. Paul had previously commanded that widows be given honor ( 1 Timothy 5:3-16). Now he commands that elders receive twice as much honor as the widows, especially those elders who work hard at preaching and teaching. [source][source][source]
"The term "honor" does not refer merely to an honorarium, but the failure to give proper pay would imply a lack of honor. The idea of "double" may refer to the double portion the oldest in the family received ( Deuteronomy 21:17). It probably consisted of the twin benefits of honor or respect and financial remuneration [1]. The fact that pay was at least included shows that those who gave leadership to spiritual affairs could expect financial support from the church (cf. 2 Corinthians 11:8-9; Galatians 6:6)." [2][source]
Another view is that the double honor did not necessarily include an honorarium or salary but consisted of the respect intrinsic to the office plus the joy of a job well done. [3][source]
"At least a part of the "double honor" Paul urged for the competent elder involved a recognition for a job well done. For us today writing a letter of gratitude, making a phone call of appreciation, and expressing a personal word of praise can accomplish the same thing." [4][source]
A third possibility is that the honor was pay, and the double honor was double pay. [5] As far as I know, no one has proved that elders in the early church typically received pay for their ministry. [source][source][source]
Note that not all the elders in the Ephesian church worked hard at preaching and teaching. This may imply that all were equally responsible to preach and teach but some did it with more diligence than others. It may mean that some elders had more responsibility to preach and teach than others (e.g, pastoral staff). Both options may be in view since both situations are common. In any group of elders one will be more diligent and or more competent in these ministries than another. 1 Timothy 5:17 probably allows for a division of labor among the elders, though all were to be "able to teach" ( 1 Timothy 3:2). [4]1 The distinction that some churches make between teaching elders and ruling elders, therefore, is essentially functional, not official. [7][source]
Paul cited two scriptural authorities to support his instruction to those who serve the church by providing leadership as elders: Moses ( Deuteronomy 25:4; Leviticus 19:13; Deuteronomy 24:15; cf. 1 Corinthians 9:9) and Jesus ( Luke 10:7; cf. Matthew 10:10). If Paul meant that both quotations were Scripture, this is one of the earliest New Testament attestations to the inspiration of another New Testament book (Luke and or Matthew; cf. 2 Peter 3:16). However, he could have meant that only the first quotation was Scripture. He may have simply added a commonly accepted truth that Jesus also quoted, which Matthew and Luke recorded, for support (cf. Mark 1:2-3). [source][source][source]