A device might include a common source, a three-dimensional array of memory cells, a plurality of access lines, and a controller. The three-dimensional array of memory cells might include a plurality of NAND strings. Each NAND string might be selectively connected between a corresponding data line and the common source. Each access line of the plurality of access lines might be connected to a control gate of a respective memory cell of each NAND string of the plurality of NAND strings. The controller might be configured to access the three-dimensional array of memory cells to implement a source-side seeding operation.