Where does the bible equate speaking in tongues with receiving the Holy spirit?

The bible teaches us that tongues are a sign of the infilling of the Holy Spirit.  On the day of Penticost, the initial outporing of the Holy Spirit, they all "Spoke in other tongues".  Peter explained this as Profised by Joel "...in the last days I will pore out my spirit" - thus the linkage is made between "Speaking in other tongues" and receiving the Holy Spirit.