Wei Collection, Middle Volume
Radical: Plow (lěi)
Page 962, Entry 20
Pronounced zi (rising tone).
Broad Rhymes (Guangyun): To heap soil around the base of seedlings.
Book of Odes (Shijing), Lesser Odes (Xiaoya): Now going to the southern fields, some weeding, some heaping soil.
Commentary: Heaping soil around the base of the plant.
Also pronounced zi (level tone).
Book of Odes (Shijing), Lesser Odes (Xiaoya): Some weeding, some heaping soil. Shen Zhong reading.
In the Collected Rhymes (Jiyun), it is also written in a variant form (zi).