We present deep GMRT OH and WSRT HI absorption spectra of the z = 0.6846 
gravitational lens toward B0218+357 .
Both the 1665 MHz and 1667 MHz OH lines are clearly detected for the first time while a new wide absorption component was detected ( at low significance ) in the HI spectrum ; the OH spectra yielded an OH column density of N _ { OH } = 2.3 \times 10 ^ { 15 } cm ^ { -2 } .
The ratio of 1667 and 1665 MHz equivalent widths is \sim 1.8 while the redshift of peak OH absorption is z = 0.68468 \pm 0.000008 for both lines ; this redshift agrees with that obtained from the HI line .
The velocity spread ( between nulls ) of the HI absorption is \sim 140 km s ^ { -1 } , while that of both OH lines is \sim 100 km s ^ { -1 } ; the HI and OH spectra are broadly similar in that they each have two principal narrow components and a wide absorption trough .
We argue that the wide absorption is likely to arise from source components in the Einstein ring and derive a rotation velocity of \sim 150 km s ^ { -1 } at a distance of 1.5 kpc from the centre of the z \sim 0.6846 galaxy .