What does Daniel 10:17 mean?
Those who encounter angels often react with intense fear (Numbers 22:31; Daniel 8:16–17; Luke 1:13, 30; 2:9–10; Acts 10:3–4). This is to be expected; angels are immensely powerful spiritual beings. Daniel is attempting to speak with such a creature (Daniel 10:5–15) but is struggling not to be overwhelmed. The combination of a troubling vision (Daniel 10:1), weeks of mourning (Daniel 10:2–3) and the dramatic appearance have taken his breath away.Fortunately, this angel—probably Gabriel (Daniel 8:15–16; 9:21–22; Luke 1:26)—is here for Daniel's benefit. The angel will provide further strength (Daniel 10:18–19) before delivering his message (Daniel 10:20–21). Not all those visited by angels are so blessed. The Lord sent an angel to Jerusalem to destroy it because David had sinned by numbering the people of Israel, but He stopped the angel from destroying the city (1 Chronicles 21:15). In another incident, a single angel killed massive numbers of invading troops just outside of Jerusalem (2 Kings 19:35–36).
Daniel's reference to "my lord" is simply polite speech, as one would speak to a superior (Daniel 1:10; 4:19). Daniel is not equating this person with the Lord God.