Like "say," the word "speak" refers to thoughts and feelings moving from our more internal spiritual levels to our more external ones -- and ultimately from the Lord, who is in a sense the most internal spiritual level of all. This is generally called "influx" and "perception" in the Writings, meaning they are thoughts and feelings that flow in in a complete way from the Lord, rather than being things we have to think about and figure out. On a number of occasions "speak" and "say" are used together; in these cases "speak" refers more to intellectual instruction in matters of thought and "say" refers more to feelings and affections that flow in directly.

53. As for the Word itself, it does not say in the prophets that they spoke it from the Holy Spirit but that they spoke it from Jehovah, Jehovah Sabaoth, or the Lord Jehovih, since it says that the Word of Jehovah came to me, that Jehovah spoke to me, and very often, Jehovah said and the saying of Jehovah. Since the Lord is Jehovah, then (as already explained [, ]), the whole Word was spoken by him.

So that no one will doubt that this is the case, I want to list the places in Jeremiah alone where it says the Word of Jehovah came to me, Jehovah spoke to me, Jehovah said, and the saying of Jehovah, which are the following: Jeremiah 1:4, 11-14, 19; 2:1-5, 9, 19, 22, 29, 31; 3:1, 6, 10, 12, 14, 16; 4:1, 3, 9, 17, 27; 5:11, 14, 18, 22, 29; 6:6, 9, 12, 15-16, 21-22; 7:1, 3, 11, 13, 19-21; 8:1, 3, 12-13; 9:3, 6-7, 9, 13, 15, 17, 22-25; 10:1-2, 18; 11:1, 6, 9, 11; 12:14, 17; 13:1, 6, 9, 11-15, 25; 14:1, 10, 14-15; 15:1-3, 6, 11, 19-20; 16:1, 3, 5, 9, 14, 16; 17:5, 19-21, 24; 18:1, 5-6, 11, 13; 19:1, 3, 6, 12, 15; 20:4; 21:1, 4, 7-8, 11-12; 22:2, 5-6, 11, 16, 18, 24, 29-30; 23:2, 5, 7, 12, 15, 24, 29, 31, 38; 24:3, 5, 8; 25:1, 3, 7-9, 15, 27, 29, 32; 26:1-2, 18; 27:1-2, 4, 8, 11, 16, 19, 21-22; 28:2, 12, 14, 16; 29:4, 8-9, 19-21, 25, 30-32; 30:1-5, 8, 10-12, 17-18; 31:1-2, 7, 10, 15-17, 23, 27-28, 31-38; 32:1, 6, 14-15, 25-26, 28, 30, 36, 42; 33:1-2, 4, 10-13, 17, 19-20, 23, 25; 34:1-2, 4, 8, 12-13, 17, 22; 35:1, 13, 17-19; 36:1, 6, 27, 29-30; 37:6-7, 9; 38:2-3, 17; 39:15-18; 40:1; 42:7, 9, 15, 18-19; 43:8, 10; 44:1-2, 7, 11, 24-26, 30; 45:1-2, 5; 46:1, 23, 25, 28; 47:1; 48:1, 8, 12, 30, 35, 38, 40, 43-44, 47; 49:2, 5-7, 12-13, 16, 18, 26, 28, 30, 32, 35, 37-39; 50:1, 4, 10, 18, 20-21, 30-31, 33, 35, 40; 51:25, 33, 36, 39, 52, 58.

These are from Jeremiah alone. It says things like this in all the other prophets and does not say that the Holy Spirit spoke or that Jehovah spoke to them through the Holy Spirit.