The Final Act On The Mount; The Giving of the Covenant Written by God (Exodus 31:18).
‘And he gave to Moses, when he had made an end of speaking with him on Mount Sinai, the two tables of the testimony, tables of stone written with the finger of God.'
God's period of fellowship and discussion with Moses (begun in Exodus 25:1) was now over and He gave to Moses two tablets which were the confirmation of the covenant and contained the covenant of the ten words which had been written by His finger, His personal written covenant with His people (see Exodus 32:15-16). These were the sign that the interview was over, and that matters were finalised.
The ten words would be in groups of five, so that there would be five on each, the covenant number twice repeated in witness. That is why they were called the Testimony. ‘The finger of God' need not be taken literally. God used His own method of inscribing the tablets. The point was that it was not Moses who had engraved the words on the tablets, but God. ‘The finger of God' was a favourite way in Egypt of speaking of any wonder that was truly of God (Exodus 8:19). (Some see two duplicate tablets with ten on each, providing copies for both parties in the covenant).
Notes to Christians.
In this chapter it is made clear that in the service of God we must receive our Spirit and wisdom from Him. Without that it will not be satisfactory (compare 1 Corinthians 2:11-16). And we learn that where God has a work that He wants done He appoints the men to do it. They are individually chosen, but along with them work a whole team of skilful craftsmen, anonymous to us but known to Him, without whom, humanly speaking, the work of God in completing the living, believing church, His temple, will not be completed.
And it is made clear that we must set apart a time for God which is wholly for Him, a time when nothing intrudes to prevent our whole attention being on Him. (And we must not only do so for ourselves, we must ensure that it is possible for others). Some may select one particular day, others may select every day, but we must be satisfied in our own minds about what we do (Romans 14:4-6), and that we do it honestly as those who must give account (Romans 14:10-12). And the keeping of such a time to God is to be a sign to Him and to the world that we belong to Him.