The blooming prosperity of Zen was over towards the end of the
Southern Sung dynasty (1127-1279), when it began to fade, not being
bitten by the frost of oppression from without, but being weakened by
rottenness within. As early as the Sung dynasty (960-1126) the
worship of Buddha Amitabha[FN#58] stealthily found its way among Zen
believers, who could not fully realize the Spirit of Shakya Muni, and
to satisfy these people the amalgamation of the two faiths was
attempted by some Zen masters.[FN#59]

[FN#58] The faith is based on Larger Sukhavati-vyuha, Smaller
Sukhavati-vyuha, and Amitayus-dhyana-sutra. It was taught in India
by Acvaghosa, Nagariuna, and Vasubandhu. In China Hwui Yuen (E-on,
died in A.D. 416), Tan Lwan (Don-ran, died in 542), Tao Choh
(Do-shaku), and Shen Tao (Zen-do) (both of whom lived about 600-650),
chiefly taught the doctrine. It made an extraordinary progress in
Japan, and differentiated itself into several sects, of which Jodo
Shu and Shin Shu are the strongest.

[FN#59] It is beyond all doubt that Poh Loh Tien (Haku-raku-ten)
practised Zen, but at the same time believed in Amitabha; so also Su
Shih (So-shoku), a most noted Zen practiser, worshipped the same
Buddha, Yang Kieh (Yo-keteu), who carried a picture of Amitabha
wherever he went and worshipped it, seems to have thought there is
nothing incompatible between Zen and his faith. The foremost of
those Zen masters of the Sung dynasty that attempted the amalgamation
is Yung Ming (Yo-myo, died in 975), who reconciled Zen with the
worship of Amitabha in his Wan Shen Tung Kwei Tsih
(Man-zen-do-ki-shu) and Si Ngan Yan Shan Fu (Sei-an-yo-sin-fu). He
was followed by Tsing Tsz (Jo-ji) and Chan Hieh (Shin-ketsu, lived