Albert Barnes on Luke 19:21

An austere man. Hard, severe, oppressive. The word is commonly applied to unripe fruit, and means sour, unpleasant, harsh. In this case it means that the man was taking every advantage, and, while he lived in idleness, was making his living out of the toils of others.

Thou takest up, &c. Thou dost exact of others what thou didst not give. The phrase is applied to a man who finds what has been lost by another, and keeps it himself, and refuses to return it to the owner. All this is designed to show the sinner's view of God. He regards him as unjust, demanding more than man has power to render, and more, therefore, than God has a right to demand. Mt 25:24.