On page 87, Muller discusses the principles of starting the Scriptural knowledge institute. Regarding prayer, Muller wrote:

We do not mean to reckon the success of the Institution by the amount of money given, or the number of Bibles distributed, but by the Lord’s blessing upon the work (Zech. 4:6); and we expect this, in the proportion in which He shall help us to wait upon Him in prayer.

While we would avoid aiming after needless singularity, we desire to go on simply according to Scripture, without compromising the truth; at the same time thankfully receiving any instruction which experienced believers, after prayer, upon Scriptural ground, may have to give us concerning the Institution.

Quotation from Page 87, 2nd paragraph; A Narrative Of Some Of The Lord’s Dealing With George Müller By George Müller, Part 1; First Edition Manuscript

In the verse quoted above, found in Luke 12:33, Jesus tells his ‘people’ to not worry: “Sell your possessions and give to the poor. Provide purses for yourselves that will not wear out, a treasure in heaven that will never fail, where no thief comes near and no moth destroys.”

He had Several points TO MAKE but here are two that show how he wants to rely on prayer at all times, not human effort or decision.

The first, that the success of work is not based on the money that we raise, or the money that we have to show, but the way that the Lord blesses the work. Secondly, that we shouldn’t ask from unbelievers but rely on the voluntary giving of believers, and God convicts them. We would do well to follow some of these principles as we serve God, letting God take control of our finances.