"The means in our possession may not seem to be sufficient for the work; but if we will move forward in faith, believing in the all-sufficient power of God, abundant resources will open before us. If the work be of God, He Himself will provide the means for its accomplishment. He will reward honest, simple reliance upon Him. The little that is wisely and economically used in the service of the Lord of heaven will increase in the very act of imparting. In the hand of Christ the small supply of food remained undiminished until the famished multitude were satisfied. If we go to the Source of all strength, with our hands of faith outstretched to receive, we shall be sustained in our work, even under the most forbidding circumstances, and shall be enabled to give to others the bread of life. DA 371.1"
"And they did all eat, and were filled: and they took up of the fragments that remained twelve baskets full."
The EGW passage uses the miracle of feeding the 5000 as an illustration of God's ability to provide resources when we act in faith. It directly references the outcome of the miracle, where everyone was filled and there were leftovers, connecting it to the idea of abundant provision.
"The Lord says, “Give, and it shall be given unto you.” “He that soweth sparingly shall reap also sparingly; and he that soweth with blessings shall reap also with blessings.... And God is able to make all grace abound unto you; that ye, having always all sufficiency in everything, may abound unto every good work; as it is written,— “He hath scattered abroad, he hath given to the poor: His righteousness abideth forever. “And He that supplieth seed to the sower and bread for food, shall supply and multiply your seed for sowing, and increase the fruits of your righteousness: ye being enriched in everything unto all liberality, which worketh through us thanksgiving to God.” Luke 6:38 ; 2 Corinthians 9:6-11 , R. V., margin. DA 371.2"
"But this I say, He which soweth sparingly shall reap also sparingly; and he which soweth bountifully shall reap also bountifully. Every man according as he purposeth in his heart, so let him give; not grudgingly, or of necessity: for God loveth a cheerful giver. And God is able to make all grace abound toward you; that ye, always having all sufficiency in all things, may abound to every good work: (As it is written, He hath dispersed abroad; he hath given to the poor: his righteousness remaineth for ever. Now he that ministereth seed to the sower both minister bread for your food, and multiply your seed sown, and increase the fruits of your righteousness;) Being enriched in every thing to all bountifulness, which causeth through us thanksgiving to God."
Ellen White directly references 2 Corinthians 9:6-11 in this passage.
"Give, and it shall be given unto you; good measure, pressed down, and shaken together, and running over, shall men give into your bosom. For with the same measure that ye mete withal it shall be measured to you again."
EGW directly quotes Luke 6:38 and 2 Corinthians 9:6-11, making this a clear explicit allusion.