KnockoutJS: Infinite recursion while modifying observable array within the subscription callback

I can't figure out why the following code snippet leads to infinite recursion:

var observableArray = ko.observableArray();
observableArray.subscribe(function (changes) {
    changes.forEach(function(change) {
        console.log("change: " + JSON.stringify(change));
        if (change.status === 'added') {
            if (change.value === "first") {
                observableArray.push("second");
            }
        }
    });
}, null, "arrayChange");

observableArray.push("first");

And here is the console log:

change: {"status":"added","value":"first","index":0}    
change: {"status":"added","value":"first","index":0}  
change: {"status":"added","value":"first","index":0}  
change: {"status":"added","value":"first","index":0}  
change: {"status":"added","value":"first","index":0}  
...  
Uncaught RangeError: Maximum call stack size exceeded  

I really don't get what is going on here. Could anyone help me, please?