We are to give of our own free will. The prophet Mosiah wrote:

And again Alma commanded that the people of the church should impart of their substance, every one according to that which he had; if he have more abundantly he should impart more abundantly; and of him that had but little, but little should be required; and to him that had not should be given. And thus they should impart of their substance of their own free will and good desires towards God, and to those priests that stood in need, yea, and to every needy, naked soul. (Mosiah 18:27-28)

The prophet Alma recounted, “And they did impart of their substance, every man according to that which he had, to the poor, and the needy, and the sick, and the afflicted” (Alma 1:27).

On the subject of giving, Elder William R. Bradford commented:

It is not the amount of money that we donate to the Church or others that matters to the Lord. Rather it is whether we give of our abundance or of our living. We should give until it is a sacrifice to give. (William R. Bradford, “Words of Jesus: Riches,” Ensign, Feb. 2003, 52 )