I have heard that on one occasion the Blessed One was staying near Sāvatthī at Jeta's Grove, Anāthapiṇḍika's monastery. And on that occasion Ven. Sāriputta was sitting not far from the Blessed One, his legs crossed, his body held erect, having set mindfulness to the fore. The Blessed One saw Ven. Sāriputta sitting not far away, his legs crossed, his body held erect, having set mindfulness to the fore.
Then, on realizing the significance of that, the Blessed One on that occasion exclaimed: